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Tom Searcy

Recent Posts by Tom Searcy

Getting Creative With AV over IP

 

One of the interesting things about AV over IP is that it offers a unique way to accomplish AV communication goals.  The rules change when your sources and end points are routed over a network; and this offers a great deal of flexibility.  An integrator recently presented some design requirements that allow an advantage with this flexibility.

 

The system called for 16 IP cameras on a network that needed to be routed to and controlled from a separate network without any Ethernet connection between the two networks.

 

The 16 cameras are connected to a layer-3 switch.  The IP addresses of each of those cameras are entered as a proxy on the decoder which has an RTSP license for hosting 3rd-party streams.  Each IP camera can provide different resolutions; and by using lower-resolution streams, the decoder does not to scale the video.  With the decoder hosting these RTSP Streams, the decoder now becomes the source into the encoder.  Usually we think of the decoder as the end point, but not in this scenario.  The connection between the two is an HDMI cable.  This addresses one of the primary requirements of the system which is security.  The customer does not want the IP cameras accessible from the network on which they are being viewed.

 

The encoder that is connected to the switch has an RTSP license that allows it to send RTSP streams to 3rd-party devices.  Viewers with access to the “viewing” network can use a soft decoder like VLC to pick up the stream via a URL.  The viewer sees whatever is on that URL which could be any of the 16 camera feeds or a combination of multiple cameras in a layout created in the VIEW® Pro Panorama Software.  The switching between these sources and layouts is accomplished using our VIEW Virtual Matrix software (see links to sample videos below) or our free Virtual Control software.  This GUI can even be accessed via a mobile device.  For more extensive control we offer free modules for all of the popular control systems.

 

https://drive.google.com/drive/folders/0B0sUvEZJUaAMMnhIOThUTmRtVWc

 

From the ClearOne side, all this requires is a single Encoder with and RTSP License and a Single Decoder with both and RTSP and a Composition license.  While it’s not something you run into every day, it is a unique way to solve a problem.  The end result is a very flexible, scalable and certainly a very cost effective solution.

 

 

 

See all of our VIEW® Pro Streaming solutions.

 

 

 

What is 4:4:4 color and why should I care?

 

In the AV industry we pride ourselves on providing the best-quality audio and visual communication to our clients.  One way in which we can do that is to offer video solutions in 4:4:4 color.

 

 

When digital video was first introduced, video files sizes were large in relation to storage and transmission capabilities.  One of the ways to address these larger file sizes was to introduce “chroma sub sampling.”  In digital video there are two main components; Luminance and Chrominance.  Luminance (or contrast) is the difference between the lightest and darkest parts of an image.  Chrominance is the color saturation of an image.  The human eye is very sensitive to small changes in contrast (Luminance) and is less sensitive to changes in color saturation (Chrominance).

 

 

To make digital video files more manageable, compression was introduced.  A true-color video signal (4:4:4) includes all of the red, green, and blue color information of each pixel.  In a 24-bit system, there are 8 pixels for each color and thus 24 bits in true color.  Chroma subsampling reduces file size by removing color.  In the AV world, the most common color space is 4:2:0, which is DVD quality. However, with 4:2:0 quality, the viewer is only seeing 50% of the available color.  To make up for that loss of color, the pixels that were removed are recreated by borrowing or “interpolating” from the adjacent pixels.  In some instances 4:2:0 quality is perfectly acceptable.  In other instances however the chroma sub sampling provides the viewer an experience that is less than optimal.

 

 

I can think of at least three instances in which 4:4:4 color is required:

 

  1. Telemedicine:  Surgical procedures streamed over a network require extremely accurate color information on the receiving end.
  2. Spreadsheets: Small text on a spreadsheet in color is virtually unreadable at anything other than 4:4:4 quality.
  3. Corporate Branding: Accurate color representation in a company logo.  Think of how some iconic brands might appear if the colors were not accurate represented.

 

 

If two video streams with identical content are placed next to each other, one at 720P 4:4:4 color and the other at 1080P 4:2:0, chances are extremely high that the average viewer will choose the lower resolution image with the true color as the more impactful.  Color trumps resolution pretty much every time.  So the next time you are specifying a streaming solution make sure to factor in which color space is most appropriate for the application.

 

Learn More about our VIEW® Pro streaming product lines and see the difference.

 

 

 

HDCP isn’t just another useless acronym

Have you ever heard of HDCP?  Ever wondered what it really means or why it exits?

 

HDCP is an acronym for High-bandwidth Digital Content Protection.  It is a form of digital copy protection that was developed by Intel with the intention of preventing the copying of digital audio and video content as it travels across connections. Being that HDCP is a digital technology, HDMI and DVI cables are used.

 

HCDP becomes relevant when it comes to moving audio and video signals over a network…..AV over IP Video Distribution.   If a signal is protected by HDCP, once that signal is put into a video distribution system, it will pass if the device the signal is flowing into is HDCP compliant.   There are two general standards in the HDCP world….1.4 and 2.XX.  Without getting into the details on either, suffice it to say that in a professional AV Distribution System, the equipment you use should be compliant with both in order to provide both a legal solution and one that is flexible for your clients needs.

 

In our industry one of the main challenges that integrators face is with Apple.  Using an Apple device as a source into an Encoder can create an issue even if the content being played is not HDCP protected.  AV Integrators have told me that their customers often call and say that their Apple Device is not passing audio and video even when the content being played is not HDCP encrypted.  By default Apple has HDCP Content protection enabled on their devices.  Apple has presumably taken this route so they will not be liable for the actions of an end user.

 

To get around this, some encoding and decoding devices have a switch that enables them to turn HDCP off.  In theory this appears to be a viable solution.  The reality however is that the HDCP licensing agreement that all manufactures who wish to be in compliance sign, does not allow for this work around.

 

With ClearOne’s View Pro System we fully support the HDCP standards of 1.4 and 2.XX.  Our View Pro AV over IP Streaming Solution will never block protected or unprotected content. There is never a need to turn HDCP off.  ClearOne has taken the position to comply with HDCP Licensing to the letter of the law.

 

For more information on HDCP, visit the link below.

 

http://www.digital-cp.com.

 

As a leader in the AV community, we must provide equipment to our partners that protect their interests and their customers.

 

 

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